A semiconductor memory device includes: a memory cell array including memory strings, one of the memory strings including memory cells; word lines commonly connected to the memory strings; and a controller configured to execute a write operation and a read operation on a page, the page being stored in memory cells connected to one of the word lines. The protection circuit comprises a first node adapted to be coupled to an anode of the light-emitting device and a second node adapted to be coupled to a cathode of the light-emitting device. For example, the water area preferably provides the cliff and cave-like areas preferred by aquatic life. The application scope is wide, and the access success probability is increased; therefore, the access quality of service provided for the user is improved.